Disability rates are extremely high in older coronary patients. Determinants of disability were determined in 44 patients with established coronary heart disease over the age of 65 years (mean 74 years). Disability score was determined from the physical function component of the Medical Outcome Study Questionnaire. Independent variables included peak aerobic capacity, rest and exercise echocardiography, body composition measures by dual x-ray absorptiometry, handgrip and leg extensor strength and a depression score. The best univariate predictors of physical function score were peak aerobic capacity (r=.67) and depression score (r=.66). Other significant univariate predictors of physical function score were handgrip and leg extensor strength. By multivariate analysis the independent predictors of physical function score were depression score and handgrip strength; both potentially modifiable factors. Physical function scores were higher in men than in women. Measures of left ventricular function did not predict physical function score. These data suggest that interventions aimed at increasing aerobic capacity and strength and at decreasing depression would improve physical function in older coronary patients. A special focus on improving physical functioning in older women is warranted due to higher disability rates.